1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly to an IPS-method liquid crystal display device which uses a thermocompression bonding conductive tape.
2. Description of the Related Art
FIG. 10 is a perspective view showing the whole constitution of a conventional liquid crystal display device.
A TFT substrate 11 and a color filter substrate 12 are made to overlap with each other with a liquid crystal layer sandwiched therebetween thus constituting a liquid crystal display panel. When an IPS-method liquid crystal display panel is used as such a liquid crystal display panel, common electrodes are not arranged on a color filter substrate side and hence, the color filter substrate is charged with static electricity. In the IPS-method liquid crystal display device, for releasing the charged static electricity, a transparent conductive film 14 made of ITO or the like is arranged on an upper surface (a surface on a side opposite to a side on which the liquid crystal layer is arranged) of the color filter substrate 12, and for grounding the transparent conductive film 14, a ground pad 15 is formed or arranged on a portion of the TFT substrate 11 where the TFT substrate 11 does not overlap with the color filter substrate 12, and the transparent conductive film 14 and the ground pad 15 are electrically connected with each other using a conductive resin 16.
Further, on a portion of the TFT substrate 11 where the color filter substrate 12 does not overlap with the TFT substrate 11, a driver chip 13 for controlling the driving of the liquid crystal display panel is formed. Further, a flexible printed circuit board 17 is arranged on the TFT substrate 11 for supplying a signal to the driver chip 13.
Here, the liquid crystal display panel is arranged above a frame-shaped mold frame 18, and one end of the above-mentioned flexible printed circuit board 17, a group of optical sheets not shown in the drawings, and a light guide plate 19 are arranged below the mold frame 18. Here, an LED light source 20 is arranged on one end of the flexible printed circuit board in a state that the LED light source 20 faces a side surface of the light guide plate 19 in an opposed manner. Further, a reflection sheet not shown in the drawing is arranged below the light guide plate 19.
As a known technique, Japanese Patent Laid-Open Hei11-149085 (patent document 1) discloses a technique in which a transparent conductive film is formed on a color filter substrate of an IPS-method liquid crystal display device.